JP2509844Y2 - 2-cycle vertical engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a two-cycle vertical engine used in a portable working machine or the like.

(Prior Art and Problems to be Solved) Conventionally, this type of engine is provided with a bearing that pivotally supports a vertical crankshaft penetrating the lower surface of the crankcase at the penetrating portion, and is a horizontal cylinder mounted on the crankcase. There is a scavenging groove that communicates with the inside of the crankcase on the inner surface of the lower part of the engine.Especially for an engine equipped with a mechanical governor between the crank arm provided on the crankshaft and this bearing, the space for installing the governor As shown in FIG. 4, the upper surface of the bearing or the bottom surface in the crankcase is located below the bottom surface of the scavenging groove of the cylinder, and therefore, the inner surface of the crankcase is not attached. The fuel in the air-fuel mixture that has flowed downward is the top surface of this bearing, the bottom surface of the crankcase, or the space around the bearing balls. Stays in a large amount. This fuel contains a large amount of lubricating oil in a two-cycle engine, and the gasoline content evaporates during operation, and the concentration of this lubricating oil tends to increase. If the engine is tilted during work, the accumulated fuel will flow into the cylinder from the scavenging groove at once, causing a temporary increase in fuel concentration and causing engine malfunction. Emission of white smoke adversely affected the hygiene of workers and the surrounding environment.

(Means and Actions for Solving the Problem) The present invention is provided with a bearing 5 for pivotally supporting a vertical crankshaft 3 penetrating the lower surface of the crankcase 1 at the penetrating portion, and is mounted on the crankcase 1 horizontally. In the engine provided with a scavenging groove 25 for communicating the combustion chamber 23 with the inside of the crankcase 1 on the inner surface of the lower portion of the cylinder 9 in the horizontal direction, a mechanical type is provided in the space inside the crankcase 1 between the crank arm 19 and the lower bearing 5. The governor 21 is provided, and in the space below the governor 21, the periphery of the bearing 5 is located below the bottom surface of the scavenging groove 25, and the step portion below the cylinder mounting portion.
It is formed as a concave portion 27 connected via 29, and the other end of the communication passage 31 communicating with the bottom surface of the concave portion 27 is provided so as to communicate with the intake passage.

A check valve 33 is provided in the communication passage 31. In addition,
The intake passage of the present invention means an intake passage from the air cleaner to the combustion chamber through the carburetor, the intake port, the crankcase, the scavenging groove.

The present invention prevents a large amount of staying by pumping the fuel, which tends to stay in the recess due to its deepness, to the intake passage through the communicating passage when the pressure of the crankcase that fluctuates according to the reciprocating motion of the piston rises. To do.

(Embodiment) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a vertical crankshaft 3 penetrating the lower surface of the crankcase 1 is supported by bearings 5. The shaft below the bearing 5 is sealed by an oil seal 7. A horizontal cylinder 9 is attached to the crankcase 1, a piston 11 is fitted to the inner surface of the cylinder 9, and the other end of a connecting rod 15 that connects one end to the piston 11 with a piston pin 13 is used as a crank. It is pivotally attached to the crank pin 17 of the shaft 3. A mechanical governor 21 is mounted between the crank arm 19 supporting both ends of the crank pin 17 and the bearing 5. On the inner surface of the lower part of the cylinder 9, the piston
At the end position where 11 has moved to the crankcase 1 side,
A scavenging groove 25 that connects the combustion chamber 23 formed on the top side of the piston 11 in the cylinder 9 and the crankcase 1 is provided. The bottom surface of the crankcase 1 around the bearing 5 is located below the bottom surface of the scavenging groove 25, and is recessed by the step 29.
27 are formed. A communication passage 31 communicating with the bottom surface of the recess 27 and the bottom surface of the bearing 5 is provided at the bottom of the crankcase 1, and the intake passage between the intake port 35 of the cylinder 9 and the carburetor 37 is provided via the check valve 33. An opening is provided in the inner diameter portion of a heat insulating insulator 39 provided therein.

In the above embodiment, when the engine 11 is operating, the air-fuel mixture sucked into the crankcase 1 moves when the piston 11 moves toward the crankcase 1 and the scavenging grooves 25 communicate with each other.
It flows into the combustion chamber 23 from the inside of the crankcase 1 through the scavenging groove 25. A part of the fuel in the air-fuel mixture adheres to the inner surface of the crankcase 1, flows down along the wall surface, and stays in the recess 27 at the bottom and in the space around the balls in the bearing 5, but the pressure in the crankcase 1 rises. Occasionally, this stagnant fuel is collected by the check valve 33.
After that, the pressure is fed from the communication passage 31 to the intake passage, and is sucked again together with the mixture. Therefore, a large amount of fuel does not stay in the recess 27 and the bearing 5.

Note that FIG. 3 shows another embodiment, and the other end of the communication passage 31 is opened at a position where the flow velocity in the scavenging groove 25 is high and therefore the pressure is reduced.

[Effect of device]

According to the present invention, a large amount of fuel contained in the air-fuel mixture does not stay at the bottom of the crankcase, so that when the engine is tilted, the fuel containing a large amount of lubricating oil is temporarily stored in the cylinder. It is possible to prevent inflow into the inside of the engine and to prevent engine malfunction, and to prevent exhaust white smoke from polluting the environment.

[Brief description of drawings]

FIG. 1 is a side sectional view of one embodiment of the present invention, FIG. 2 is a sectional explanatory view of a main portion of FIG. 1, FIG. 3 is a side sectional view of another embodiment, and FIG. It is a sectional side view. 1 …… Crankcase 3 …… Crankshaft 9 …… Cylinder 25 …… Scavenging groove 27 …… Concave 31 …… Communication passage 33 …… Check valve

Claims (4)

(57) [Scope of utility model registration request] 1. A combustion chamber is provided on a lower inner surface of a horizontal cylinder 9 mounted on the crankcase 1, the bearing 5 supporting a vertical crankshaft 3 penetrating a lower surface of the crankcase 1 at the penetrating portion. In an engine provided with a scavenging groove 25 for communicating 23 with the inside of the crankcase 1, a mechanical governor 21 is provided in the space inside the crankcase 1 between the crank arm 19 and the surrounding of the lower bearing 5, and a mechanical governor 21 is provided below the governor 21. In the space, the periphery of the bearing 5 is located below the bottom surface of the scavenging groove 25, and the stepped portion below the cylinder mounting portion.
A two-cycle vertical engine, characterized in that it is formed as a recess 27 connected via 29, and the other end of a communication passage 31 communicating with the bottom surface of this recess 27 is provided so as to communicate with the intake passage. 2. A two-stroke vertical engine according to claim 1, wherein the communication passage 31 is provided with a check valve 33. 3. A two-cycle vertical engine according to claim 1, wherein the other end of the communication passage 31 is connected to an intake passage between the intake port of the cylinder 9 and the carburetor. 4. The two-cycle vertical engine according to claim 1, wherein the other end of the communication passage 31 is communicated with the scavenging groove 25.